Rationale for use of the Clinical Dementia Rating Sum of Boxes as a primary outcome measure for Alzheimer's disease clinical trials.

BACKGROUND: We used the database of the Alzheimer's Disease Neuroimaging Initiative (ADNI) to explore the psychometric properties of the Clinical Dementia Rating Sum of Boxes (CDR-SB) to consider its utility as an outcome measure for clinical trials in early and mild, as well as later, stages of Alzheimer's disease (AD). METHODS: We assessed internal consistency, structural validity, convergent validity, and 2-year internal and external responsiveness of the CDR-SB using data from 382 subjects with early or mild AD at entry into the ADNI study. RESULTS: The CDR-SB assesses both cognitive and functional domains of AD disability. Mean scores declined nearly linearly; CDR-SB cognitive and functional subsums contributed equally to total scores at both very mild (early) and mild stages of the disease. CONCLUSIONS: The CDR-SB has psychometric properties that make it attractive as a primary outcome measure that comprehensively assesses both cognitive and functional disability in AD patients. It may prove particularly useful for studies in early, predementia stages of AD.

Natalizumab for the treatment of active Crohn's disease: results of the ENCORE Trial.

BACKGROUND & AIMS: A randomized placebo-controlled trial evaluated the efficacy of natalizumab induction therapy in patients with Crohn's disease. METHODS: Patients (N = 509) with moderately to severely active Crohn's disease and active inflammation characterized by elevated C-reactive protein concentrations were randomized (1:1) to receive natalizumab 300 mg or placebo intravenously at Weeks 0, 4, and 8. The primary end point was induction of response (> or =70-point decrease from baseline in the Crohn's Disease Activity Index score at Week 8 sustained through Week 12). Additional efficacy end points included the proportion of patients with sustained remission (Crohn's Disease Activity Index score <150 points) and response or remission over time. RESULTS: Response at Week 8 sustained through Week 12 occurred in 48% of natalizumab-treated patients and 32% of patients receiving placebo (P < .001). Sustained remission occurred in 26% of natalizumab-treated patients and 16% of patients receiving placebo (P = .002). Week 4 response rates were 51% for natalizumab and 37% for placebo (P = .001). Responses remained significantly higher at subsequent assessments (P < .001) in natalizumab-treated patients. Natalizumab-treated patients also had significantly higher remission rates at Weeks 4, 8, and 12 (P < or = .009). The frequency and types of adverse events were similar between treatment groups. CONCLUSIONS: Natalizumab induced response and remission at Week 8 that was sustained through Week 12. Response and remission rates for natalizumab were superior to those for placebo at Weeks 4, 8, and 12, demonstrating the early and sustained efficacy of natalizumab as induction therapy in patients with elevated C-reactive protein and active Crohn's disease. Natalizumab was well tolerated in this study.